Iron(III)-Catalyzed Four-Component Coupling Reaction of 1,3-Dicarbonyl Compounds, Amines, Aldehydes, and Nitroalkanes: A Simple and Direct Synthesis of Functionalized Pyrroles

Abstract

A simple, convenient, and multicomponent coupling strategy for the synthesis of highly functionalized pyrroles catalyzed by iron(III) salts has been developed. This strategy demonstrated four-component coupling reactions of 1,3-dicarbonyl compounds, amines, aromatic aldehydes, and nitroalkanes without an inert atmosphere. This methodology provides an alternative approach for easy access of highly substituted pyrroles in moderate to very good yields using four simple and readily available building blocks via one-pot tandem reaction. Notably, this method is very cheap, straightforward, and environmentally friendly compared to the existing methods.

Transition Metal-Mediated Synthesis of Monocyclic Aromatic Heterocycles

“…The reaction tolerates a variety of aliphatic and aromatic substituents producing pyrroles in regioselective fashion (Scheme 324). 486 In 2011, Pal reported a more versitile Pd-catalyzed version of this transformation. 487 …”

1,3-Diketones. Synthesis and properties

“…Polysubstituted pyrroles 173 were synthesized by one-pot four-component reaction of aromatic aldehydes with primary amines, 1,3-diketones (1 : 1.5 : 1), and nitromethane, catalyzed by 10 mol % of FeCl 3 [124] (Scheme 105). Analogous four-component con-densation of acetylacetone with amines, aldehydes, and nitromethane in ionic liquid ([Hbim] BF 4 ) without a catalyst gave pyrrole derivatives 174 [125] (Scheme 106).…”

Efficient, Three-Component Synthesis of Pyrrole Derivatives Catalyzed by Iodobenzene and Oxone

“…New methodologies for pyrrole synthesis include intramolecular cyclization, [5][6][7] transition-metal catalyzation, [8][9][10][11] and multi-component reactions. [12][13][14][15] All these methods are suffering from drawbacks of tedious workups, use of toxic or expensive transition metals, and unavailability of the starting materials. Therefore, simple method to synthesize pyrrole derivatives under mild reaction conditions is still desirable.…”